Application of chemical compounds to control plant pathogens has had quite a few adverse consequences for natural environments and human health. Biological control agents are desired to avoid or remediate these adverse effects. Biological control agents, such as microorganisms, may confer plant disease control by suppressing disease incidence and/or reducing the severity of symptoms caused by the pathogens.
Effective biological control of plant diseases with epiphytic microbes has been used with numerous phyllosphere- and rhizosphere-inhabiting organisms. Foliar biological control agents have included yeast and filamentous fungi, as well as bacteria; including gram negative species such as Erwinia sp. and Pseudomonas sp., and gram positive organisms such as Bacillus sp. It is thought that biological disease control is attributed to direct antagonism against the pathogen such as by production of antibiotics or hydrolytic enzymes. or through competition for nutrients, though other mechanisms such as the induction of systemic resistance responses within the plant have also been attributed to biocontrol agents.
What is needed are compositions comprising biological control agents, such as bacteria, and methods for preventing and/or reducing plant disease by affecting plant pathogen activity and effect on the plants.